Polymeric detergents



Patented New, 1948 Q 2,454,541 POLYMERIC DETERGENTS Louis B. Bock,Huntingdon Valley, and James L. Bainey, Abingfon, Pa., asslgnors tojtohm& Haas Company, Philadelphia, Pa., a corporatlon of Delaware No Drawing.Application September 9, 1944,

Serial No'. 553,476

- 1' This invention relates to surface-active or capillary-activeagents. tion of materials which have high detergent action under a widevariety of conditions. More specifically, it relates to the preparationand use of polymeric, water-soluble detergents which have high molecularweights and contain within each molecule a multiplicity of hydrophobicand hydrophilic groups or portions so arranged and balanced as to becomeoriented at an interface.

It is generally recognized that surface-active agents, as, for example,alkali-metal soaps or quaternary ammonium compounds, exist in water inthe form of micelles. While the exact nature of such micelles is notestablished, there is evidence that they are electrically chargedaggregates of molecules. For example, when a sodium soup of a fatty acidis dispersed in water, it dissociates into positively charged sodiumions and into negatively charged micelles which are aggregates of soapmolecules and some negative ions. Because the micelles carry a negativecharge, this type of soap is known as an anion-active detergent. Incontrast, detergents of the type of quaternary ammonium compounds yieldpositively charged micelles in aqueous solution and, hence, are known ascation-active soaps or agents. This conception of the formation ofmicelles is based on measurements of freezing points, vapor pressures,and electrical conductivities of aqueous dispersions of surface-activeagents. It is further recognized that surface activity is related to theformation of such micelles and to the orientation of the micelles at aninterface.

The individual molecules in colloidal micelles are held together only byphysical forces or by weak secondary valences; and, as a result, theextent of micelle formation depends upon the prevailing conditions, andit is affected by such factors as the concentration of thesurface-active agent, the presence of electrolytes, solvents, and

6 Claims. (01. zoo-'3) It relates to the prcparato make the use of suchdetergents uneconomical and often impractical. Furthermore, thematerials are ineffective in many laundering operations whereinextremely hot water is used in order to accelerate the removal of soil.7

The products of this invention differ from-and have advantagesoverdetergents known heretofore in that their effectiveness is notdependent upon the formation of loosely bound micelles. By the processof this invention, water-soluble macromolecules are synthesized in whichall of the bonds between atoms are primary valence links and, hence, arestrong and are not affected by such factors as concentration andtemperature. Furthermore, the synthesized macromolecules containbalanced hydrophilic and hydrophobic groups so positioned in themacromolecule 'that orientation can and does occur readily at aninterface.

The products of this invention may be made rials which are in factmacromolecules and then other surface-active agents, and also upon thetemperature. Thus, dilution of the solution, elevation of thetemperature, or a change in the amount of any salts which may also bepresent in solution favor the reversion of micelles into simplemolecules and/or ions with the formation of true solutions. As anexample, synthetic detergents known heretofore have no value at very lowconcentrations or in very hot water because under these conditions themicellar structure reverts, the molecules then exist in true solution,and, as a result, detergency is lost. The necessity of using relativelyhigh concentrations plus the higher cost of synthetic detergentscombines introducing into said macromolecules hydrophilic groups. Thehydrophilic groups, which impart water solubility, may be ether-alcoholgroups or esterified ether-alcohol groups and are introduced, forexample, by the reaction of ethylene oxide or propylene oxide with themacromolecule. If desired, the terminal hydroxyl of said etheralcoholgroup may be converted into a, salt-forming ester group of a polybasicacid.

The resultant products may be considered to have three functionalportions. Thus, they contain (a) as the hydrophobic portion, thehydrocarbon groups attached to the phenol nucleus; (b) as thehydrophilic portion, the modified or unmodified ether-alcohol groups,and (c) as the polymeric portion, the phenol nuclei joined by methylenebridges. The hydrocarbon groups attached to the phenol and the modifiedor unmodified ether-alcohol groups also attached to the phenol are sobalanced as to assure water solubility and orientation at an interface.At the same time, the polymeric nature of the product assures such ahigh molecular weight that the product is in fact a macromolecule whichimparts capillary.- or surface-activity to a solution, as do micelles ofordinary soaps, but which is stable and is not dissociated as are themicelles of customary detergents under adverse conditions.

The above discussion is for purposes of theoretical explanation only,and it must be understood that the so-called three portions of themacromolecule are not independent of each other 3 but are all combinedin one large molecule which functions as a concerted whole.

The type of hydrocarbon group which is attached to the phenol-nucleusmay vary as to kind but in every case must contain at least four carbonatoms. In reality, substituting groups of at least eight carbon atomsare much preferred. Generally, it is preferred that the substituenthydrocarbon group be a straight or branched chain acyclic group, such asn-butyl, iso-butyl, tertiary butyl, amyl, tertiary amyl, n-octyl,diiso-butyl, decyl, 'dodecyl, hexadecyl, octadecyl, and the like.Alternatively, phenols substituted with alicyclic groups may be used.These are typified by cyclohexyl phenol, methyl-cyclohexyl phenol,butyl-cyclohexyl phenol. and dicyclchexyl phenol. While aryl-substitutedphenols, such as p-phenyl phenol and p-naphthyl phenol, may be employedthey are less satisfactory than those listed above unless they in turncontain an alkyl group. Thus, p-tolyl phenol is much preferred thoughnot preferred, it may be in a. form such as a formal or hexamethylenetetramine which will yield formaldehyde under the conditions ofreaction.

Ordinarily, the substituted phenol and formaldehyde are reacted bycondensing together in the presence of an acidic or alkalinecondensation catalyst until the products have become relatively viscous.Solvents may be employed. Acidic condensation catalysts are preferredbecause of the ease with which the condensation may be controlled.Elevated temperatures naturally accelerate the rate of reaction.Condensation of formaldehyde and substituted phenols such as are hereinvolved do not proceed to the infusible stage and, accordingly, nolimit need be imposed upon the degree of condensation. In practice, itis convenient to follow the extent of condensation by means of viscositymeasurements and the condensation may be halted at an early stage atwhich the molecular weight is low and the product on the average has nomore than three or four phenolic units per molecule, or it may becontinued until each macromolecule contains many more units. Thecondensation products may range in physical properties from oils tobrittle solids, depending upon the degree of condensation and the natureof the substituent hydrocarbon group on the phenol.

Hydrophilic of water-solubilizing groups may be introduced by condensingwith the substituted phenol-formaldehyde macromolecule an alkylene oxidesuch as ethylene oxide, a propylene oxide such as trimethylene oxide orisopropylene oxide, or a butylene oxide such as isobutylene oxide. Thecondensation is preferably conducted in the presence of an alkalinecatalyst such as the hydroxides of the alkali metals, although in someinstances no catalyst is required. While the reaction may be carried onat lower temperatures 1 and at atmospheric pressure in the presence oftures above 100 C. under superatmospheric pressure with or withoutsolvents. More than one mol of alkylene oxide is employed and, in fact,it is preferred to use at least eight mols per mol of phenol condensedin macromolecule. The product, which is water soluble and hascapillaryaction properties, may be represented by the formula In theformula, R represents a hydrocarbon substituent of four or more carbonatoms, R represents an alkylene group from the class consisting ofethylene, propylene, and butylene groups, p is an integer having a,value of 8 or above and preferably from 10 to 20, inclusive, and a: isan integer greater than 1.

It must be understood that mixtures of the alkylene oxides, such as amixture of ethylene and propylene oxides, may be employed, although itis preferred to use individual oxides.

Alternatively, detergents having the above general formula may be madefrom the sodium derivative of the phenol-formaldehyde condensate and ahalohydrin of a polyglycol such as CI.(C2H4O)1C2H4OH, BI(C2H4O)mCzI-LOH, or Cl(C3H'1O) QCaH'IOH.

The products are best described as surfaceactive polymeric productscontaining in their chemical structure hydrocarbon-substituted phenoxypolyalkoxy alcohol units in which units said hydrocarbon substituentcontains at least four carbon atoms and said alcohol contains at leasteight oxygen-linked alkylene groups from the class consisting ofethylene, propylene, and butylene groups, at least three of said unitsbeing joined in each molecule by means of methylene bridges. The productmay be esterifled or etherified or otherwise modified to producedetergents of unusual properties. Such modifications are the subjects ofother of our applications.

The following examples will serve to illustrate the preferred method ofpreparing the surfaceactive products of this invention,

Example 1 reflux condenser was charged the following: 412

grams of a,a,y;y-tetramethylbutylphenol, 162 grams of a 37% aqueoussolution of formaldehyde, and 27.6 grams of water. The mixture wasagitated and heated to a temperature of C. At this point, 246 grams ofoxalic acid and 0.92 gram of Twitchell's reagent dissolved in ten gramsof water were added. While being agitated, the reaction mixture wasrefluxed for six hours. Two hundred grams of water and 384 grams oftoluene were added, and refluxing was continued for an hour. Agitationwas stopped and the contents of the flask were removed to a separatoryfunnel. The aqueous and resinous layers were separated and the solventwas removed from the resinous layer by vacuum distillation. After theremoval of the solvent, heating at a reduced pressure of 1.5 to 2.5 mm.and at a temperature of 245 to 250 C. was continued for four andone-half hours. The condensate then had a viscosity of 4.0 poises whenmeasured as a 60% solution in toluene and, on cooling, solidified to abrittle mass.

Step 2.A mixture of 118 parts of the product of Step 1, having hydroxylnumber 01260, two parts of solid Nell, and 100 parts of toluene washeated to 125? to 150 C.in an autoclave. Ethylen'e oxide was addedslowly over a period of two and one-half hours until 261 parts ofethylene oxide were absorbed. This corresponds to eleven mols ofethylene oxide per mol of phenol in the product of step 1. The toluenewas then removed by steam distillation and the water 'by vacuumdistillation at 100 C. The product was obtained as a viscous pastehaving a-corrected hydroxyl number of 97. It was readily soluble inwater and had marked detergent properties. Its formula may berepresented by the following:

0(c,H.0)".H o(c=u.o)u.n ILI: CH O 7 on!" J: a can Ezample 2 Step 1.-Anoctadecyl phenol-formaldehyde condensate was prepared by heating a.mixture of 346v parts (1.0 mol) of octadecylphenol, 81 parts (1.0 mol)of 37% formaldehyde, 18.8 parts of water, 1.23 parts of oxalic acid. and0.46 partof Twitchell's reagent for seven hours under reflux. Onehundred ninety-two parts of toluene and 150 parts of water were added,and refluxing was continued for one-half hour. The aqueous layer waswithdrawn and the toluene layer concentrated by removal of toluene underreduced pressure. The residue was finally heated for five 'hours at 250C. at a pressure of 1.5 mm. of mercury. The product was a soft, viscousmaterial, insoluble in water and having a hydroxyl the use of ethyleneoxide, it is understood that a propylene oxide or a butylene' oxide maybe employed in a similar manner. In order to impart a given degree ofwater-solubility, it is advisable to use a greater amount of the higheroxides than the amount of ethylene oxide required.

considerably above twenty to one. In fact, detergents have been preparedin which the ratio was ashighassixty toone. Insuchcasa, the length ofthe hydrophobic group was also increased in order to assure a balancebetween the hydrophilic or water-solubilizing portions and thehydrophobic or water-insolubilizing portions.

In the above exampls, the ethylene oxide is slowly added to the heatedsolution of the phenolic con Altanatively, all of thematerialsmaybemixedattheoutsetandthenreacted at an elevated temperature,provided that preca are taken to dissipate the heat evolved during thereaction.

Alloftheproductsofthisinventionfunctlon as capillary-active orsurface-active agents. As such, they become oriented at an interface,lower thesurfacetmsionofwater,andcausemore'rapidwetiangofsurfacessuchasthesurfacesot as measured bythe standardDraves Sinking Test. Their outstanding property is their efiectivenessas detergents. In this capacity, as w H1 by tests and laundering tests,they are oding and are far superior to soaps and synthetic detergentshown heretofore.

As deter-grunts the products described hereinmaybeusedinhardwaterorinwateroihigh salt content. They may be employedunder acidic or i. m tions. Their advantage over syntheidc mts rrsidesin the fact that they are not mi but are in fact macromolecules which donot revert as do micella. Thus, they are cut dets at very lowconcentrations or at very high temperatures where former syntheticdetergents failed. They are uncommonly advantageous in the laimdering orcotton fabrics and in the securing of wool, sized, dyed, and printedfabrics in general. 'Iheybeusedforpreparingdispersions-of oil in wateror dispersions of polymerizabie materials prior to the polymerizationthereof. Aiso,-they serve to break water-in-oil emulsions such as areencountered in oil-fields. And they have been found to be verysatisfactory in the trea of leather, in the dispersion of pigments, andas assistants in dyeing.

Theotthisinventicnare particularly useful when used in conjunction withother capillary-active agents, including fatty acid soaps Furthermore,as the entire length of the hydrophilic group is increased, the productordinarily becomes morewater-soluble. It is, therefore, advisable toincrease the hydrophobic group proportionately. This can be done byincreasing the size of the hydrocarbon substituent of the phenol, asrepresented by R in theabove general formula. In this way, a balance ismaintained between the hydrophilic and hydrophobic portions of themacromolecule so that the product is water-soluble and at the same timecapillary-active, in that it becomes oriented at an interface.

A lowerlimit of eight mols of alkylene oxide per mol of phenol has beenindicated above together with a preferred ratio of ten to twmty mols ofoxide per mol of phenol. It is to be unand synthetic detergents such asthose shown in United States Patents 2,115,192 and 2,143,759. Suchcombinations have high degrees of wetting and detergent properties.

We claim:

1. Water-soluble, ploymeric detergents formed by by heating (a) one molof a. phenol having the formula.

hiwhichRisasaturatedhydrocarbonsubstitderstood that the upper limit ofthe ratio can be 15' uent containing eight to eighteen carbon atoms,

- detergents formed by condensing by heating (a) in which R is asaturated hydrocarbon substituent containing eight to eighteen carbonatoms, and (b) from 0.5 to 1.0 mol of formaldehyde, and then reactingtherewith (c). from eig t to sixty mols of ethylene oxide.

4. Water-soluble, polymeric detergents formed by condensing by heating(a) one mol of a phenol having the formula in which R is a saturatedhydrocarbon substituent containing eight to eighteen carbon atoms, and(b) from 0.5 to 1.0 mol of formaldehyde, and then reacting therewith (c)from ten to twenty mols of ethylene oxide.

5. Water-soluble, surface-active, polymeric one mol of octyl phenol and(b) from 0.5 to 1.0 mol of formaldehyde and then reacting therewith (c)from 10 to 20 mols of ethylene oxide.

6. Water-soluble, surface-active, polymeric detergents formed bycondensing by heating (a) one mol of octadecyl phenol and (b) from 0.5to 1.0 mol of formaldehyde and then reacting therewith (c) from 10 to 20mols of ethylene oxide.

. LOUIS H. BOCK.

JAMES L. W.

REFERENCES CITED The following references are of record in the tile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,917,250 Harris July 11, 19331,917,257 Harris July 11, 1933 2,046,318 Brubaker July 7, 1936 2,060,410Balle Nov. 10, 1936 2,076,624 De Groote Apr. 13, 1937 OTHER REFERENCESClayton-Theory or Emulsions, published by Blakiston 00., Philadelphia,Pa., 4th ed. (1943),

page 127.

